XML 36 R23.htm IDEA: XBRL DOCUMENT v3.7.0.1
Stock-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2016
Stock-Based Compensation Expense Related to Common Stock Options, Restricted Common Stock and Common Stock Warrants

Following is the stock-based compensation expense related to common stock options, restricted common stock and common stock warrants:

 

     Year Ended December 31,  
           2016                  2015        

Research and development

   $ 831      $ 1,018  

General and administrative

     1,648        2,382  
  

 

 

    

 

 

 

Total stock-based compensation expense

   $ 2,479      $ 3,400  
  

 

 

    

 

 

 
Weighted Average Assumptions Used to Determine Fair Value of Options Granted

The fair value of the options granted is determined using the Black-Scholes option-pricing model. The following weighted average assumptions were used:

 

     2016     2015  

Risk-free interest rate

     1.49     1.65

Expected life of the options

     6 years       6 years  

Expected volatility of the underlying stock

     96     101

Expected dividend rate

     0     0
Summary of Stock Option Activity

The following table summarizes the stock option activity in the stock based compensation plans:

 

     Number of
Shares
     Weighted
Average
Exercise
Price
     Weighted
Average
Remaining
Contractual
Life
(in years)
     Aggregate
Intrinsic Value
(in thousands)
 

Outstanding, December 31, 2014

     3,332,617      $ 5.79        

Granted

     454,000        3.23        

Forfeited/Cancelled

     (348,718      4.42        

Exercised

     (95,574      1.80        
  

 

 

    

 

 

       

Outstanding, December 31, 2015

     3,342,325      $ 5.70        

Granted

     1,434,750        0.97        

Forfeited/Cancelled

     (120,187      3.41        

Exercised

     —          —          
  

 

 

    

 

 

    

 

 

    

 

 

 

Outstanding, December 31, 2016

     4,656,888      $ 4.30        6.83      $ 120  
  

 

 

    

 

 

    

 

 

    

 

 

 

Exercisable, December 31, 2016

     3,384,238      $ 5.44        5.78      $ 22  
Summary of Additional Information Regarding Outstanding and Exercisable Options under Stock Based Compensation Plans

The following table summarizes additional information regarding outstanding and exercisable options under our stock based compensation plans at December 31, 2016:

 

     Options Outstanding      Options Exercisable  

Exercise

Price (Range)

   Number of
Shares
     Weighted
Average
Remaining
Contractual
Life
     Weighted
Average
Exercise
Price
     Number of
Shares
     Weighted
Average
Exercise
Price
 
            (in years)                       

$0.87 – 1.00

     1,157,250        9.9      $ 0.88        206,250      $ 0.88  

$1.37 – 1.83

     341,668        8.2        1.45        197,147        1.51  

$2.08 – 2.79

     810,000        6.0        2.28        703,999        2.21  

$3.45 – 4.41

     564,517        7.3        3.82        498,712        3.87  

$6.24 – 7.56

     1,466,953        4.2        6.99        1,466,953        7.00  

$13.38

     316,500        7.0        13.38        311,177        13.38  
  

 

 

          

 

 

    
     4,656,888        6.8      $ 4.30        3,384,238      $ 5.44  
  

 

 

          

 

 

    
Summary of Restricted Stock Grant Activity

The following table summarizes the restricted stock grant activity in the Company’s equity incentive plans from December 31, 2014 through December 31, 2016:

 

     Shares  

Outstanding, December 31, 2014

     416,670  

Granted

     337,935  

Exercised

     —    

Options forfeited/cancelled

     —    
  

 

 

 

Outstanding, December 31, 2015

     754,605  

Granted

     —    

Exercised

     —    

Options forfeited/cancelled

     —    
  

 

 

 

Outstanding, December 31, 2016

     754,605